Why does my model's edges are too hard?
The texture and lighting on the second image make it seem smoother since it's harder to distinguish between the faces, even though it has very similar geometry.
To fix this issue, you can select the mesh, go to the Object menu at the top of the viewport, and click on shade smooth. This will make the object appear smooth even though it has fairly simple geometry. However, this approach can cause some issues with shading and lighting not appearing realistic.
If shading smooth doesn't fix the appearance well enough, try using a subdivision surface modifier to add more faces to the mesh and give it a rounder appearance. You can use this modifier and the shade smooth option for the best results.